[AWS::CloudFormation::Macro] - [Docs] - Cross Region lambdas not supported

### Name of the resource

AWS::CloudFormation::Macro

### Resource name

_No response_

### Reference Link

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/template-macros.html#template-macros-permissions

### Details

The Lambda Function that is used for a Macro must be in the same region that the Macro is defined. You may create the Macro while pointing to a lambda function hosted on a different region, however all attempts to execute the Macro will fail with a "Failed to execute" error.

This is undocumented in the [Macro](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/template-macros.html#template-macros-permissions) and [AWS::CloudFormation::Macro](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-cloudformation-macro.html#cfn-cloudformation-macro-loggroupname) documentations.

Here is a[ stack overflow page](https://stackoverflow.com/questions/60531198/cloudformation-macro-to-use-cross-region-lambda) that states this behavior.

Start with the linked template-macros permissions section and the AWS::CloudFormation::Macro documentation. Confirm the same-region Lambda requirement described in the issue, then update both linked documentation pages so the restriction and failure behavior are explicit.

Written by the indexing model from the issue text.